Which of the following sets is closed under subtraction?

A boy weighs 31.5 kilograms. How much does he weigh in pounds?

So is this the correct answer

A man and a woman agree to meet at a certain location about 12:30 p. m. if the man arrives at a time uniformly distributed between 12:15 and 12:45 and the woman independently arrives at a time uniformly distributed between 12:30 and 1 pm, find the

In a trapezoid, three interior angles measure 80°, 100°, and 140°. What is the measure of the fourth interior angle.

In Hawaii, sales tax is 4.0 % what is the total (including tax) on items that total $136.55 before tax?

One month Boris rented 2 movies and 5 video games for a total of $33. The next month he rented 8 movies and 3 video games for a total of $30. Find the rental cost of each movie and you each video game.

When the cost of a car is multiplied by 0.05 the result is $1720. find the cost of the car.?

Is this correct? 11y+8 = 130 -8 - 8 11y = 122 :11 : 11 Y = 11.091

Order these numbers from least to greatest. - 193, - 38, 6.23, - 6.5

A teacher has 15 weeks in which to teach six chapters. Write and then solve an equation, showing all work, that represents the number of lessons the teacher must teach per week if there is an average of 8.5 lessons per chapter.